scholarly journals New Perspective on Wood Thermal Modification: Relevance between the Evolution of Chemical Structure and Physical-Mechanical Properties, and Online Analysis of Release of VOCs

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1145 ◽  
Author(s):  
Jiajia Xu ◽  
Yu Zhang ◽  
Yunfang Shen ◽  
Cong Li ◽  
Yanwei Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dimensional Stability ◽  
Chemical Structure ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Decay Resistance ◽  
Thermal Modification ◽  
Infrared Spectrometry ◽  
Dominant Component ◽  
New Perspective

Thermal modification (TM) is an ecological and low-cost pretreated method to improve the dimensional stability and decay resistance of wood. This study systematically investigates the relevance between the evolution of chemical structure and the physical and mechanical properties during wood thermal modification processes. Moreover, the volatility of compounds (VOCs) was analyzed using a thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TGA-FTIR) and a pyrolizer coupled with gas chromatography/mass spectrometer (Py-GC/MS). With an increase of TM temperature, the anti-shrink efficiency and contact angle increased, while the equilibrium moisture content decreased. This result indicates that the dimensional stability improved markedly due to the reduction of hydrophilic hydroxyl (–OH). However, a slight decrease of the moduli of elasticity and of rupture was observed after TM due to the thermal degradation of hemicellulose and cellulose. Based on a TGA-FTIR analysis, the small molecular gaseous components were composed of H2O, CH4, CO2, and CO, where H2O was the dominant component with the highest absorbance intensity, i.e., 0.008 at 200 °C. Based on the Py-GC/MS analysis, the VOCs were shown to be mainly composed of acids, aldehydes, ketones, phenols, furans, alcohols, sugars, and esters, where acids were the dominant compounds, with a relative content of 37.05−42.77%.

scholarly journals Physical and Mechanical Properties of Heat Treated Daniella oliveri (Africa Balsam Tree) Wood

2019 ◽  
pp. 1-9 ◽  
Author(s):  
Ebenezer Adeyemi Iyiola ◽  
Babatola Olufemi ◽  
Victoria Olubukola Oyerinde ◽  
J. M. Owoyemi ◽  
Ayanleye Samuel
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Compressive Strength ◽  
Study Design ◽  
Dimensional Stability ◽  
Treated Wood ◽  
Physical And Mechanical Properties ◽  
Thermal Modification ◽  
Average Weight ◽  
Direction Parallel

Aims: This work investigated the effect of thermal modification on some of the physical properties and mechanical properties of Daniella oliveri wood. Study Design: The study design used for this experiment was 3 x4 Factorial experiment in Completely Randomized Design. Place and Duration of Study: The study was conducted at the Federal University of Technology, Akure wood laboratory and the study lasted for 6 months. Methodology: Wood samples were thermally treated at the temperature of 120, 140, 160 and 180°C, for different durations of 1, 1.5 and 2 hours in a muffle furnace. The planks were air-dried to reduce the moisture content and then machined into the required dimensions in the direction parallel to grain with a circular saw. Thirty-nine defect-free samples of dimensions 20 mm × 20 mm × 60 mm were prepared for dimensional stability and compression test, static bending tests and the hardness tests to make a total of 117 samples. Results: The result showed that the average weight loss of the treated wood samples varied from 3.79% at 120°C for 1 hour to 7.51% at 180°C for 2 hours. The treatment led to reduction in density from 528 to 459 kg/m3 at 180°C for 2 hours. The heat treatment also led to reduction in water absorption and volumetric swelling of the treated samples. The mean value for Modulus of elasticity (MOE) ranges from 2.17x103 N/mm2 to 2.96 x 103 N/mm2 for the treated samples while the untreated was 2.22x103 N/mm2. Heat treatment brought about improvement in the maximum compressive strength and the Janka hardness parallel to the grain of wood samples. The value of compressive strength increased from 26.58 N/mm2 to 41.71 N/mm2 and hardness from 69.24 N to 75.5 N. It can therefore be concluded that thermal modification greatly enhanced the dimensional stability and mechanical properties of wood samples.

scholarly journals Physical and Mechanical Properties of Natural Leaf Fiber-Reinforced Epoxy Polyester Composites

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1369
Author(s):  
Sanjeev Kumar ◽  
Lalta Prasad ◽  
Vinay Kumar Patel ◽  
Virendra Kumar ◽  
Anil Kumar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Synthetic Fibre ◽  
Low Cost ◽  
Fibre Length ◽  
Physical And Mechanical Properties ◽  
Natural Fibres ◽  
Risk Environment ◽  
Insulation Property ◽  
Natural Leaf

In recent times, demand for light weight and high strength materials fabricated from natural fibres has increased tremendously. The use of natural fibres has rapidly increased due to their high availability, low density, and renewable capability over synthetic fibre. Natural leaf fibres are easy to extract from the plant (retting process is easy), which offers high stiffness, less energy consumption, less health risk, environment friendly, and better insulation property than the synthetic fibre-based composite. Natural leaf fibre composites have low machining wear with low cost and excellent performance in engineering applications, and hence established as superior reinforcing materials compared to other plant fibres. In this review, the physical and mechanical properties of different natural leaf fibre-based composites are addressed. The influences of fibre loading and fibre length on mechanical properties are discussed for different matrices-based composite materials. The surface modifications of natural fibre also play a crucial role in improving physical and mechanical properties regarding composite materials due to improved fibre/matrix adhesion. Additionally, the present review also deals with the effect of silane-treated leaf fibre-reinforced thermoset composite, which play an important role in enhancing the mechanical and physical properties of the composites.

Fire-Retardant Plastering Mortars Based on Exfoliated Vermiculite and Volcanic Ash

2021 ◽  
Vol 1043 ◽  
pp. 133-139
Author(s):  
Tolya Khezhev ◽  
Artur Zhurtov ◽  
Alim Kazharov ◽  
Tamerlan Zrumov ◽  
Asharbek Samgurov
Keyword(s):  
Mechanical Properties ◽  
Volcanic Ash ◽  
Cement Mortar ◽  
Low Cost ◽  
Fire Retardant ◽  
Physical And Mechanical Properties ◽  
Strength Characteristics ◽  
Multifunctional Additive ◽  
Solution Density ◽  
Noticeable Increase

The research results on the development of fire-retardant composite cement mortar mixtures on exfoliated vermiculite and volcanic ash with the use of a multifunctional additive are presented D-5. Compositions of fire-retardant composite mortars, which make it possible to significantly improve the physical and mechanical properties of mortar mixtures and mortars, are proposed. Introduction of a multifunctional supplement D-5 in mortar mixtures makes it possible to improve the composite mortar mixtures properties and improve the solution characteristics. Replacement of finely dispersed fraction of exfoliated vermiculite d<0,63 mm volcanic ash by volume in mortar mixtures does not cause a noticeable increase in the solution density, while their strength characteristics increase. The developed composite mortar mixtures meet the requirements of GOST 28013–98 and have a low-cost price due to volcanic ash use.

scholarly journals Effect of punching on physical and mechanical properties of leathers: Focus on car seat covers

2019 ◽  
Vol 14 ◽  
pp. 155892501989056
Author(s):  
Eui Kyung Roh
Keyword(s):  
Mechanical Properties ◽  
Apparent Density ◽  
Coefficient Of Friction ◽  
Dimensional Stability ◽  
Physical And Mechanical Properties ◽  
Air Permeability ◽  
Car Seats ◽  
Car Seat

As a lot of time is spent in the car, the comfort of not only the car seat but also the car seat cover itself has become of increasing importance. With increasing use of ventilated seats, the control of the physical and mechanical properties of leather in response to punching has become of prime importance in the design of car seats. This study evaluated the changes in the physical and mechanical properties of leather due to punching and proposes optimum punching intervals for car seats. Sixteen types of leather, punched at three spatial intervals (2, 3, and 5 mm), were evaluated in terms of their apparent density, softness, coefficient of friction, warm-cool feeling, and mechanical properties. Leather punching affected its physical and mechanical properties. However, there were differences in punching intervals that significantly affected each property, including the mechanical properties. Depending on the performance required when developing a product, a suitable punching interval must be selected. Therefore, punching at 5 mm intervals is preferred for obtaining physical and mechanical properties similar to those of untreated leathers, and punching at 3 mm intervals is recommended for achieving more softness. On the contrary, punching at 2 mm intervals increases air permeability but decreases dimensional stability.

scholarly journals PLA/PHA-Biodegradable Blends for Pneumothermic Fabrication of Nonwovens

2016 ◽  
Vol 16 (3) ◽  
pp. 119-127 ◽  
Author(s):  
Krzysztofa Szuman ◽  
Izabella Krucińska ◽  
Maciej Boguń ◽  
Zbigniew Draczyński
Keyword(s):  
Mechanical Properties ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Chemical Structure ◽  
Wide Spectrum ◽  
Physical And Mechanical Properties ◽  
Polymer Composition ◽  
Attenuated Total Reflectance ◽  
Total Reflectance ◽  
The Fourier Transform

Abstract This study presents the results of research concerning fabrication of nonwovens from biodegradable polymer blends using the melt-blown method. The experiments performed within the framework of the research confirmed the possibility of obtaining polymer composites based on polylactide (PLA) with poly(hydroxyalkanoates) (PHA) and another aliphatic-aromatic copolyester. The obtained products were subjected to the analyses of chemical structure using the Fourier Transform Infrared Spectroscopy(FTIR) Attenuated Total Reflectance(ATR) method. The physical and mechanical properties of the fabricated nonwoven layers were also tested, which confirmed a wide spectrum of their applicability, depending on the polymer composition used in production.

A study of mineral coal physical and mechanical properties changes in thermal modification process

2016 ◽  
pp. 3-8
Author(s):  
V. A. Arsentyev ◽  
◽  
A. M. Gerasimov ◽  
S. V. Dmitriev ◽  
A. D. Samukov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Thermal Modification ◽  
Modification Process

scholarly journals Joint Effect of Steel Addition and Press-and-Sinter on the Properties of Low-Cost PM Ti Alloys

2018 ◽  
Vol 770 ◽  
pp. 248-254
Author(s):  
Leandro Bolzoni ◽  
Elisa Maria Ruiz-Navas ◽  
Elena Gordo
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Biomedical Applications ◽  
Low Cost ◽  
Physical And Mechanical Properties ◽  
Steel Powder ◽  
Joint Effect ◽  
Ti Alloys ◽  
Commercial Steel ◽  
Processing Techniques

Cheap alloying elements and creative processing techniques are a way forward to open up more industrial opportunities for Ti in sectors where it is not extensively applied yet, rather than in aerospace and biomedical applications. This study focuses on understanding the joint effect of using a commercial steel powder to add Fe to pure Ti and its processing by press-and-sinter on the behaviour of low-cost PM Ti alloys. It is found that the calibrated addition of steel permits to develop new low-cost Fe-bearing Ti alloys that can satisfactorily be produced using the blending elemental PM approach. Densification of the samples and homogenization of the chemical composition are enhanced by the high diffusivity of Fe. The low-cost α+β alloys reach comparable physical and mechanical properties to those of wrought-equivalent PM Ti alloys, such as Ti-6Al-4V, and are therefore promising candidates for load-bearing lightweight products.

Physical and mechanical properties of sulfonated aromatic copolyimide membranes

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Ahmad Rabiee ◽  
Shahram Mehdipour-Ataei
Keyword(s):  
Mechanical Properties ◽  
Chemical Structure ◽  
Physical And Mechanical Properties ◽  
Xrd Analysis ◽  
Polymeric Films ◽  
Solid Polymer ◽  
Plastic Behavior ◽  
Thermally Stable ◽  
Sem Micrograph ◽  
Ion Conducting

AbstractPhysical and mechanical properties of four series of chemically and thermally stable sulfonated copolyimides as ion-conducting ionomers for application in fuel cell membrane, depending on chemical structure of diamine monomers were studied. The physical and mechanical properties of solid polymer membranes including thermal stability, mechanical strength, water uptake, stability in water, crystallinity and morphology were evaluated. All the polymers were thermally stable. The XRD analysis and SEM micrograph revealed that the polymers were almost amorphous and hydrophobic-hydrophilic phase separation in polyimide did not occur. Use of flexible monomers such as 4,4'-oxydianiline (ODA) and 4,4'-(4-aminophenoxy) diphenylsulfone (APDS) in the hydrophobic sequences increased the plastic behavior compared to rigid polymers prepared from 4,4'-(5- amino-1-naphthoxy) diphenylsulfone (ANDS) and m-phenylenediamine (m-PDA). It was concluded that the properties of polymeric films were strictly dependent on chemical composition of monomers and molecular weight of copolymers.

Physical and Mechanical Properties of Five Heat-Treated Hardwood Species

2012 ◽  
Vol 472-475 ◽  
pp. 1132-1134
Author(s):  
Jin Sun ◽  
Xiao Bo Wang ◽  
Xiao Jing Wang ◽  
Yan Lin ◽  
Zhen Zhong Gao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Dimensional Stability ◽  
Negative Impact ◽  
Physical And Mechanical Properties ◽  
Betula Platyphylla ◽  
Fraxinus Mandshurica ◽  
Hardwood Species ◽  
Heat Treated ◽  
Betula Platyphylla Suk

Five hardwood species (Schima superba Gardn, kapur( Dryobalanops sp.), ash (Fraxinus mandshurica Rupr.), birch(Betula platyphylla Suk.), tauari (Couratari sp.)) were conducted the Heat treatment at 185°C.. The results indicated that the dimensional stability, modulus of elasticity (MOE) increased greatly while the wettability decreased after treatment. There was a negative impact of heat treatment on MORs.

scholarly journals Utilization of diverse cheap materials as pore generating agent to manufacture low-cost porous ceramic

Cerâmica ◽  
2020 ◽  
Vol 66 (378) ◽  
pp. 179-185
Author(s):  
M. M. Salman ◽  
N. S. Radhi ◽  
O. H. Sabr ◽  
H. T. Nhabih
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Mercury Intrusion Porosimetry ◽  
Corn Starch ◽  
Low Cost ◽  
Porous Ceramic ◽  
Physical And Mechanical Properties ◽  
Soaking Time ◽  
Paper Waste ◽  
Sodium Feldspar

Abstract Paper waste, corn starch, and sawdust were utilized as pore generating agents to produce a porous ceramic. Kaolin clay, sodium feldspar, and 20% of pore generating agent were mixed, and the samples were formed by mold method, dried at room temperature for about 72 h and in a furnace at 115 ºC for 5 h, and then fired at 1200 ºC with a soaking time of 3 h. The samples were tested for measurement of physical and mechanical properties and the microstructure was evaluated by scanning electron microscopy and mercury intrusion porosimetry. The results showed that the sample prepared with corn starch had the highest porosity, lowest mechanical properties and permeability, and smallest pore size, while the characteristics of the sample prepared with sawdust were contrary; finally, the sample of paper waste had the highest permeability and intermediate values of other properties.

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